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Commit 2e88beb1 authored by Elliot Berman's avatar Elliot Berman
Browse files

firmware: qcom_scm: Support SCM calls before qcom_scm probe 



Lazily initialize qcom_smc_convention with a wrapper. Required for
SCM calls that occur before qcom_scm probe time.

Change-Id: I408b7ac6efc62b7e88846bc4769d66fccf2e7c0a
Signed-off-by: default avatarElliot Berman <eberman@codeaurora.org>
parent bdce1764

drivers/firmware/qcom_scm-64.c

+54 −27
Original line number Diff line number Diff line
@@ -67,6 +67,8 @@ enum qcom_smc_convention { 


static enum qcom_smc_convention qcom_smc_convention = SMC_CONVENTION_UNKNOWN;

static DEFINE_MUTEX(qcom_scm_lock);

static bool has_queried;

static DEFINE_SPINLOCK(query_lock);



#define QCOM_SCM_EBUSY_WAIT_MS 30

#define QCOM_SCM_EBUSY_MAX_RETRY 20
@@ -200,6 +202,9 @@ static int qcom_scm_call_smccc(struct device *dev, 
		smc.a[i + SMCCC_FIRST_REG_IDX] = desc->args[i];



	if (unlikely(arglen > SMCCC_N_REG_ARGS)) {

		if (!dev)

			return -EPROBE_DEFER;



		alloc_len = SMCCC_N_EXT_ARGS * sizeof(u64);

		args_virt = kzalloc(PAGE_ALIGN(alloc_len), flag);
@@ -342,6 +347,9 @@ static int qcom_scm_call_legacy(struct device *dev, struct qcom_scm_desc *desc) 
	__le32 *arg_buf;

	__le32 *res_buf;



	if (!dev)

		return -EPROBE_DEFER;



	cmd = kzalloc(PAGE_ALIGN(alloc_len), GFP_KERNEL);

	if (!cmd)

		return -ENOMEM;
@@ -426,6 +434,48 @@ static int qcom_scm_call_atomic_legacy(struct device *dev, 
	return res.a0;

}



static void __query_convention(void)

{

	unsigned long flags;

	struct qcom_scm_desc desc = {

		.svc = QCOM_SCM_SVC_INFO,

		.cmd = QCOM_SCM_INFO_IS_CALL_AVAIL,

		.args[0] = SMCCC_FUNCNUM(QCOM_SCM_SVC_INFO,

					 QCOM_SCM_INFO_IS_CALL_AVAIL) |

			   (ARM_SMCCC_OWNER_SIP << ARM_SMCCC_OWNER_SHIFT),

		.arginfo = QCOM_SCM_ARGS(1),

		.owner = ARM_SMCCC_OWNER_SIP,

	};

	int ret;



	spin_lock_irqsave(&query_lock, flags);

	if (has_queried)

		goto out;



	qcom_smc_convention = SMC_CONVENTION_ARM_64;

	ret = qcom_scm_call_smccc(NULL, &desc, true);

	if (!ret && desc.res[0] == 1)

		goto out;



	qcom_smc_convention = SMC_CONVENTION_ARM_32;

	ret = qcom_scm_call_smccc(NULL, &desc, true);

	if (!ret && desc.res[0] == 1)

		goto out;



	qcom_smc_convention = SMC_CONVENTION_LEGACY;

out:

	has_queried = true;

	spin_unlock_irqrestore(&query_lock, flags);

	pr_debug("QCOM SCM SMC Convention: %d\n", qcom_smc_convention);

}



static inline enum qcom_smc_convention __get_convention(void)

{

	if (unlikely(!has_queried))

		__query_convention();

	return qcom_smc_convention;

}



/**

 * qcom_scm_call() - Invoke a syscall in the secure world

 * @dev:	device
@@ -439,7 +489,7 @@ static int qcom_scm_call_atomic_legacy(struct device *dev, 
static int qcom_scm_call(struct device *dev, struct qcom_scm_desc *desc)

{

	might_sleep();

	switch (qcom_smc_convention) {

	switch (__get_convention()) {

	case SMC_CONVENTION_ARM_32:

	case SMC_CONVENTION_ARM_64:

		return qcom_scm_call_smccc(dev, desc, false);
@@ -464,7 +514,7 @@ static int qcom_scm_call(struct device *dev, struct qcom_scm_desc *desc) 
 */

static int qcom_scm_call_atomic(struct device *dev, struct qcom_scm_desc *desc)

{

	switch (qcom_smc_convention) {

	switch (__get_convention()) {

	case SMC_CONVENTION_ARM_32:

	case SMC_CONVENTION_ARM_64:

		return qcom_scm_call_smccc(dev, desc, true);
@@ -770,7 +820,7 @@ int __qcom_scm_is_call_available(struct device *dev, u32 svc_id, u32 cmd_id) 
	};



	desc.arginfo = QCOM_SCM_ARGS(1);

	switch (qcom_smc_convention) {

	switch (__get_convention()) {

	case SMC_CONVENTION_ARM_32:

	case SMC_CONVENTION_ARM_64:

		desc.args[0] = SMCCC_FUNCNUM(svc_id, cmd_id) |
@@ -929,28 +979,5 @@ int __qcom_scm_qsmmu500_wait_safe_toggle(struct device *dev, bool en) 


void __qcom_scm_init(void)

{

	int ret;

	struct qcom_scm_desc desc = {

		.svc = QCOM_SCM_SVC_INFO,

		.cmd = QCOM_SCM_INFO_IS_CALL_AVAIL,

		.args[1] = SMCCC_FUNCNUM(QCOM_SCM_SVC_INFO,

					 QCOM_SCM_INFO_IS_CALL_AVAIL) |

			   (ARM_SMCCC_OWNER_SIP << ARM_SMCCC_OWNER_SHIFT),

		.arginfo = QCOM_SCM_ARGS(1);

		.owner = ARM_SMCCC_OWNER_SIP,

	};



	qcom_smcc_convention = ARM_SMCCC_SMC_64;

	ret = qcom_scm_call_smccc(NULL, &desc, true);

	if (!ret && desc.res[0] == 1)

		goto out;



	qcom_smcc_convention = ARM_SMCCC_SMC_32;

	ret = qcom_scm_call_smccc(NULL, &desc, true);

	if (!ret && desc.res[0] == 1)

		goto out;



	qcom_smc_convention = SMC_CONVENTION_LEGACY;

out:

	pr_debug("QCOM SCM SMC Convention: %d\n", qcom_smc_convention);

	__query_convention();

}